I read all the posts in this regard but no solution.
Everything worked fine with the theme Terrifco. This morning I switched to MP Pro Theme and now this error is coming up. I verified that I am in live mode and checked the API data 10 times and compared to PayPal. This is a little annoying since I have not changed diddly squat but the theme from Terrifco to MP Pro and a test purchase on Friday with Terrifco theme worked fine.
Need some held please